Sinking Driveway Repair Options

Why Your Driveway Is Sinking—and Why You Should Act Fast

A level driveway is something most homeowners take for granted—until the day you notice a dip, a sudden drop-off near the garage, or a crack deep enough to catch a snow-shovel blade. Sinking concrete or asphalt isn’t just an eyesore; it’s a tripping hazard, a tire-killer, and an open invitation to water damage under your slab and into your foundation. The good news? Modern sinking driveway repair options are faster, cheaper, and less disruptive than most people think—if you pick the right method before the problem snowballs.

Early Warning Signs of a Sinking Driveway

Catch the problem early and you’ll save hundreds (sometimes thousands) in repair costs. Walk your driveway every spring and fall and look for:

• Hairline cracks that widen after rain: Water is washing out the base.
• Small “birdbath” puddles: Low spots collect water, accelerating settlement.
• Gap between the garage floor and driveway: A classic sign of soil shrinkage or poor compaction.
• Uneven joints: If one slab is ¼ in. lower than its neighbor, frost heave or base erosion is underway.

Tip: Lay a 4-ft. level across joints. Any reading over ⅛ in. per foot means you’re on the clock.

What’s Really Going On Underground?

Poor Soil Compaction

Most driveways sink because the sub-grade wasn’t compacted properly when the house was built. Clay-heavy soils expand and contract, creating voids under the slab.

Water Erosion

Downspouts dumping next to the driveway, leaky sprinkler lines, or a negative slope toward the house wash out gravel base layers.

Burrowing Pests & Tree Roots

Chipmunks, groundhogs, and even decaying tree stumps leave tunnels that collapse under load.

Frost Heave & Thaw Cycles

In northern zones, repeated freezing lifts concrete slightly; when it thaws, the soil underneath may not return to the same volume, causing settlement.

Sinking Driveway Repair Options: From Quick Fixes to Full Replacement

Below are the four methods professional driveway companies propose, ranked from least to most invasive. Prices are typical for a standard two-car, 20×20 ft. section (400 sq ft) in the Midwest—adjust 10-20 % for coasts.

1. Mudjacking (Slabjacking)

How it works: 1-in. holes are drilled through the slab and a sand-cement “slurry” is hydraulically pumped underneath, lifting the slab back to grade.

• ✅ Proven 80-year-old tech, great for heavy loads (RV pads, garage aprons)
• ✅ 24-hour cure time
• ❌ Slurry weighs 100 lbs/cu ft—can exacerbate settlement on loose soils
• ❌ Larger injection holes (1–1⅛ in.) are visible if you look closely

Cost: $4–$6 per sq ft ($1,600–$2,400 total)

Best for: 4–8 in. settlement on older concrete in good condition.

2. Polyurethane Foam Injection (PolyLift)

How it works: Two-part expanding foam is injected through ⅜-in. holes. Foam expands 20× original volume, filling voids and lifting slab within minutes.

• ✅ Lightweight (2–4 lbs/cu ft), won’t add weight to soil
• ✅ 15-minute traffic-ready cure—great for busy households
• ✅ Hydro-insensitive: works in wet conditions
• ❌ Higher material cost
• ❌ Requires certified tech; DIY kits rarely achieve even lift

Cost: $6–$9 per sq ft ($2,400–$3,600 total)

Best for: Decorative stamped concrete, newer slabs, or when you need same-day use.

3>3. Partial Slab Replacement

How it works: Saw-cut and remove the settled section, re-compact sub-grade, pour new concrete or asphalt, then seal the joint.

• ✅ Brand-new surface where tires roll most (garage lip, apron)
• ✅ Opportunity to fix drainage (install trench drain, reroute downspout)
• ❌ New concrete rarely matches older slabs in color or texture
• ❌ Cold joints can separate again if base isn’t stabilized

Cost: $10–$14 per sq ft for concrete ($4,000+ for 400 sq ft), $4–$6 for asphalt overlay.

Best for: Sections with spider cracks, spalling, or vertical drop >3 in.

4. Full Removal & Rebuild

How it works: Everything comes out—concrete, base, sometimes soil—then geo-textile, 6 in. compacted crushed stone, and new 5-in. reinforced slab.

• ✅ Fixes underlying problem permanently
• ✅ Lets you widen, add turn-around, or heat cables
• ❌ 5–7 days out of commission
• ❌ Highest price, permit may be required

Cost: $12–$18 per sq ft ($4,800–$7,200 total)

Best for: Severe widespread settlement, multiple cracks, or when you’re selling soon and want a transferable warranty.

Can You Fix a Sinking Driveway Yourself?

Only the smallest asphalt dips (≤1 in.) are realistic DIY projects. Sweep out debris, trowel in cold-patch, compact with a 4×4 or hand tamper, then sealcoat the area. For concrete, skip the YouTube “slab jack with spray foam” hacks—uneven lift usually cracks the slab, and expanding foam can push your footer sideways. Licensed contractors carry $1 M+ liability and equipment that meters lift within 1/10 in.

How to Choose the Right Repair Method

1. Measure the drop. <2 in. → foam or mudjack; >3 in. → consider replacement.
2. Check slab age & condition. Surface is sound? Lift it. Map cracking everywhere? Replace.
3. Evaluate drainage. If water still runs toward the house, fix grade or gutters first or the new slab will sink again.
4. Get at least two quotes. Ask for psi of foam (minimum 50 lbs) or slurry compressive strength (minimum 500 psi).
5. Ask for warranty length and transferability. Foam companies often offer 5-year; full-replacement contractors 10-year.

Hidden Costs & Smart Add-Ons

• Sealing joints: $1–$1.50 per lin ft—prevents future water intrusion.
• Downspout extensions: $15 each at big-box, save $1,000+ in future settlement.
• Permit fees: $50–$200 for replacement in many municipalities—factor into bid.
• Night/weekend surcharge: Foam crews may add 10 % if you need driveway open by 6 a.m. Monday.

Post-Repair Maintenance Tips

Keep your investment level:

• Seal cracks every fall with polyurethane caulk rated for concrete.
• Redirect downspouts ≥5 ft from driveway edge.
• Avoid rock-salt in first winter after new concrete; use calcium-chloride instead.
• Don’t park heavy dumpsters or RVs on the same spot for more than a week.

Frequently Asked Questions